• The Journal of the Korean bone and joint tumor society
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• v.11 no.2
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• pp.155-159
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• 2005

Purpose: To find out the pathologic symptoms, and the incidence and clinical significance of the coexistence of internal derangement of knee(IDOK) in osteochondroma around the knee. Materials and Methods: We retrospectively reviewed forty-five patients under 20 years of age treated with the excision of the osteochondroma around the knee between 1995 and 2004. We analyzed age, gender, past history, family history, solitary or multiple osteochondroma, presenting pathologic symptoms, and causes of IDOK. Results: IDOK was confirmed in nine(20%) among the 45 cases. There were four cases of multiple osteochondromatosis, and IDOK was coexisted in one case among them. The most common presenting pathologic symptoms were painless mass of 38 cases, however 9 cases among them had joint pain for IDOK. There were 7 cases of meniscal tears and 2 of pathologic plica. Discoid meniscus was found in 4 cases among the 7 cases of meniscal tears. Conclusion: Coexistence of osteochondroma around knee and IDOK in this study probably represents a coincidence rather than a real association. However the incidence might be not low, special study and close observation should be done.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.2
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• pp.121-123
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• 2011

The medial patellar plica may cause symptoms when it becomes thickened and fibrotic because of direct trauma or repetitive sporting activities. The medial plica syndrome has been noticed as one of major causes of internal derangement and well documented in the articles. A few cases of the bucket handle tear of the medial plica are described in liteartures. To our knowledge, however, there have never been reported about it in domestic literatures. We present a case of the bucket handle tear of the medial plica resected by arthroscopic surgery with a review of the relevant articles.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.108-111
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• 2006

We present a case of double medial plica that developed on right knee joint. There has been no documented case of double medial plica of the knee joint. In a general way, double medial plica syndrome is very difficult to diagnose because it does rarely develop and symptoms are non-specific or not present. It is difficult to distinguish between pain originating from the medial plica and from other internal derangement of the knee. This patient had symptoms including aggravating right knee pain with sitting position or knee flexion for 3 months. We performed MRI and arthroscopy for more accurate diagnosis. MRI T1, T2 images showed typical double medial plica and we had performed arthroscopic excision of symptomatic medial plica in right knee joint. Arthroscopic resection provided satisfactory relief of symptom.lasting and satisfactory relieve of symptom.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.150-154
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• 1999

Fenestrated medial patellar plicae are unusual. These fenestrated medial plica may vary in size and shape from being small circular and 5mm in diameter to being large opening 3-4cm long. Arthroscopic resection of the painful medial plica can provide lasting and satisfactory relief of symptoms. There is high percentage of associated medial knee symptoms that are relieved by complete resection. We had performed arthroscopic excision of the symptomatic fenestrated medial plicae present in both knees. The symptoms were dramatically relieved after arthroscopic surgery.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.73-77
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• 1999

Purpose : The purpose of the study was to evaluate the sensitivity and specificity of proton-weighted fast spin-echo MR imaging in diagnosing the meniscal tear of knee as an reasonable substitute for conventional spin-echo imaging. Materials and Methods : 102 consecutive patients, proved by surgery, proved by surgery, were participated in this study. All of them were suspected internal derangement of knee, examined by fast spin-echo MR imaging including sagittal and coronal images on a 1.5T MR imager and underwent arthroscopic or open surgery of knee joint within 2 months. These images were reviewed retrospectively by three radiologists. The sensitivity and specificity of meniscal tear were calculated. Results : The sensitivity and specificity of meniscal tear using proton-weighted fast spin-echo MR imaging were 94%, 93% inmedialmeniscus and 92%, 88% in lateral meniscus. Conclusion : The sensitivity and specificity of meniscal tear using proton weighted fast-spin echo MR images were as high as those using conventional spin-echo images. The proton-weighted fast-spin echo MR imaging can be an alternative to conventional spin-echo MR imaging in diagnosing meniscal tear of the knee.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.153-157
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• 2003

Purpose: To identify injuries and profile the characteristics of injured skiers and to use this information in designing injury-prevention programs and protective equipment. Materials and Methods: Injured skiers treated at a clinic of a ski resort located in Kangwon province in Korea were reviewed from 1998 to 2001. An injury was defined as any accident occurred during alpine skiing that required medical treatment. All injured skiers were asked to fill in a questionnaire which documented the mechanism of injury, their experiences , and the slope where they were injured Results: 1197 patients experienced ski injuries over a three-year-period. The overall incidence of ski injuries was 6.4 injuries per 1000 skiers. There was a slightly higher proportion of men than women and the mean age was in the third decade. The injury rate was higher for beginners and for less difficult slopes . The sprain and ligament injuries were most common and knee injuries accounted for 30$\%$ of all ski injuries . Conclusion: In our study , ski injuries occurred more often compared with foreign reports. it was concluded that an insufficient injury prevention system, an increasing number of skiers and a growing proportion of beginners was responsible for such a result.

• Journal of IKEEE
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• v.23 no.2
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• pp.388-394
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• 2019

This paper describes a design of security system-on-chip (SoC) that integrates a Cortex-M0 CPU with an AAW (ARIA-AES- Whirlpool) crypto-core which implements two block cipher algorithms of ARIA and AES and a hash function Whirlpool into an unified hardware architecture. The AAW crypto-core was implemented in a small area through hardware sharing based on algorithmic characteristics of ARIA, AES and Whirlpool, and it supports key sizes of 128-bit and 256-bit. The designed security SoC was implemented on FPGA device and verified by hardware-software co-operation. The AAW crypto-core occupied 5,911 slices, and the AHB_Slave including the AAW crypto-core was implemented with 6,366 slices. The maximum clock frequency of the AHB_Slave was estimated at 36 MHz, the estimated throughputs of the ARIA-128 and the AES-128 was 83 Mbps and 78 Mbps respectively, and the throughput of the Whirlpool hash function of 512-bit block was 156 Mbps.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.171-179
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• 2011

Feistel and SPN are the two main structures in a block cipher. Feistel is a symmetric structure which has the same structure in encryption and decryption, but SPN is not a symmetric structure. Encrypt round function and decrypt round function in SPN structure have three parts, round key addition and substitution layer with S-box for confusion and permutation layer for defusion. Most SPN structure for example ARIA and AES uses 8 bit S-Box at substitution layer, which is vulnerable to Square attack, Boomerang attack, Impossible differentials cryptanalysis etc. In this paper, we propose a SPN which has a symmetric structure in encryption and decryption. The whole operations of proposed algorithm are composed of the even numbers of N rounds where the first half of them, 1 to N/2 round, applies a right function and the last half of them, (N+1)/2 to N round, employs an inverse function. And a symmetry layer is located in between the right function layer and the inverse function layer. The symmetric layer is composed with a multiple simple bit slice involution S-Boxes. The bit slice involution S-Box symmetric layer increases difficult to attack cipher by Square attack, Boomerang attack, Impossible differentials cryptanalysis etc. The proposed symmetric SPN block cipher with bit slice involution S-Box is believed to construct a safe and efficient cipher in Smart Card and RFID environments where electronic chips are built in.

• Physical Therapy Korea
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• v.9 no.4
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• pp.61-68
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• 2002

본 연구는 하퇴의지 착용자와 정상 성인간의 시간-거리, 운동형상학 변수를 조사하고 비교하기 위하여 실시하였다. 연구 대상자는 외상으로 인한 하퇴 절단자로서 내골격식 하퇴의지를 착용하고 독립적으로 보행이 가능한 20명과 연령, 신장으로 짝짓기한 대조군(matched control group) 20명이 참여하였다. 보행분석은 Vicon Clinical Manager Software (VCM)를 내장한 PC에 5개의 카메라가 연결되어 있는 Vicon 512 Motion Analysis System (MAS, Oxford Metrics Inc.)을 이용하였다. 하퇴의지 착용군의 단하지 지지시간이 정상 성인군에 비해 유의하게 짧았으며(p<.05), 하퇴의지 착용군에서 슬관절의 선전이 증가되었으며 족관절의 저측굴곡이 감소되었다(p<.05). 하퇴절단자들의 보행개선을 위해서는 하퇴절단자 개인의 보행능력에 알맞은 부품의 선택, 체계적인 보행훈련 및 평가, 보행능력 향상을 위한 근력강화 프로그램 등 체계적인 재활훈련 프로그램이 필요한 것으로 사료된다. 본 연구는 연구대상자의 수가 제한되어 있으므로 연구의 결과를 일반화하기에는 제한점이 있으나, 향후 편측 하퇴절단자의 보행연구에 대한 기초 자료로 사용될 수 있을 것이라고 생각된다.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.2
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• pp.168-174
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• 2005

Purpose: We experienced 8 cases of osteoid osteoma arising around hip joint which had some characteristics that differ from those arising on long bone. we reports the characteristics of osteoid osteoma arising around the hip joint. Materials and Methods: 8 cases of osteoid osteoma were diagnosed during 1985 to 2004 at hanyang university hospital. all cases were comfirmed patholgically. 6 cases were male, 2 cases were female patients. The mean age was 17 years old (ranged from 8 to 29). They occurred in intertrochanteric area (4 cases), subtrochanteric area (2 cases), acetabulum (1 case) and femoral neck (1 case). We used radiologic tools including magnetic resonance image, computed tomography, bone scintigraphy. clinicopathologic test including erythrocyte sedimentation rate and Creactive protein. Results: The patients expressed various symptoms including thigh pain, knee pain, low back pain and radiating pain respectively. 2 patients had experienced operation on knee joint. 3 patients showed limping gait. Aspirin relieved the pain in 3 patients. The difference in circumference was 1cm between both thighs in 2 cases. Conclusion: Patients with osteoid osteoma arising around hip joint which have various symptoms such as severe knee pain and claudication, differ from infectious disease by clinicopathologic test including erythrocyte sedimentation rate and C- reactive protein and had better diagnostic result in computed tomography.